The following invention relates to a processing circuit for use in a digital camera system which allows a visual event to be captured in a memory whenever that event falls outside the range of a user-defined visual image.
Electronic test instruments such as oscilloscopes display visual waveforms on a CRT screen or other visual medium to provide a visual depiction of activity within a device under test. It is sometimes desirable with such instruments to have photographic records of the waveforms resulting from certain tests displayed on the oscilloscope. Heretofore, cameras have been developed which are adapted to be clipped or mounted to the front of the oscilloscope for taking pictures of visual events displayed on the CRT screen. Such cameras have not, however, been capable of digital signal processing.
A desirable feature in such cameras would be the ability to selectively capture certain visual events that fit a predetermined event characteristic. For example, if as a result of certain tests, a certain waveform is expected to be displayed on the oscilloscope, it may be desirable to have a photographic record of any waveform displayed that deviates from the expected waveform by some predetermined amount. This feature has been available in digital oscilloscopes as shown in Dagostino et al. U.S. Pat. No. 4,510,571, but has not been available in cameras adapted for photographing oscilloscope traces.